This invention relates to wind power turbines and more particularly to a vertical axis type wind power turbine.
Generally, various wind power turbines converting a wind power energy to a rotary motion have been already suggested and practiced. Such wind power turbines are largely divided into propeller type (horizontal axis type) wind power turbines and vertical axis type wind power turbines. In the propeller type wind power turbine among them, unless the propeller rotating disk is rightly aligned with the wind direction, the rotating efficiently will be so low that, in case the wind power turbine is to be located in a place where the wind direction varies, it will be necessary to always rightly align the propeller rotating disk with the wind direction by providing a device following the wind direction. On the other hand, the vertical axis type wind power turbine is omni-directional and is not influenced at all by the wind direction. Therefore, the primary advantage of the vertical axis wind turbine over its horizontal counterpart lies in the simplicity of the basic configuration.
However, if such airfoil as is usually used for aircraft is adopted for the blade of the above mentioned vertical axis type wind power turbine, the efficiency of the turbine will not be so high as it potentially is. Therefore, a system of periodically controlling the blade fitting angle with the rotation of the turbine is suggested to improve the efficiency of the wind power turbine. However, in this cyclic control system, a complicated costly control device is required to be introduced and the feature of the above described vertical axis type windmill can not be well realized.